Poultry houses must be ventilated and cooled to prevent the mortality of the poultry when the sum of the ambient temperature and the relative humidity inside the poultry house exceeds a known value. It is generally accepted that when the sum of the ambient temperature, measured in degrees Fahrenheit, and the relative humidity exceeds about 180, the poultry can easily suffer mortality. Most poultry farmers agree that it is necessary to reduce the ambient temperature inside the poultry house when the sum of the temperature and the relative humidity exceeds about 160. To this end, it is desirable to maintain the ambient temperature inside the poultry house at or below about 82 degrees Fahrenheit.
A common ventilation system for ventilating and cooling a poultry house includes an extended opening formed in at least one of the sidewalls of the poultry house, and one or more large exhaust fans positioned in a smaller opening formed in one of the sidewalls adjacent an endwall, or formed in the endwall itself A curtain is secured to the exterior surface of the sidewall, and may be raised as necessary in response to the ambient temperature and the relative humidity to ventilate and cool the inside of the poultry house. The fan exhausts the hot air inside the poultry house and draws fresh air from outside the poultry house through the extended opening formed in the sidewall to replace the air that is exhausted. In many climates, the ambient temperature of the air outside the poultry house is too high during at least a portion of the calendar year to cool the poultry house to 82 degrees Fahrenheit or below.
Accordingly, as shown in FIGS. 1a and 1b, many ventilation systems are equipped with an evaporative cooling system positioned adjacent the extended opening formed in the sidewall. Typically, the evaporative cooling system 10 includes at least one fan 21, at least one evaporative cooling pad 12 mounted adjacent the extended opening 13 formed in the sidewall 14, and a means 16 for wetting the evaporative cooling pad with a liquid, such as water, so that the air drawn into the poultry house through the opening 13 is cooled below the ambient temperature of the air outside the poultry house. The evaporative cooling pad 12 is typically made of an absorbent material, such as cellulose, and may be wetted by a recirculated liquid. Typically, however, the evaporative cooling pad 12 is wetted by a plurality of spray nozzles 18 positioned on a framework 19 supported adjacent the sidewall 14 and directed onto the evaporative cooling pad 12.
The spray nozzles 18 emit a fine mist of water onto the exterior surface 11 of the evaporative cooling pad 12 for a predetermined interval of time according to a cycle command from a conventional timer (not shown). The cycle command opens, and later closes, a solenoid (not shown) which is in fluid communication with the spray nozzles 18 and a supply of water. To produce the fine mist, the spray nozzles are required to have a very small diameter. Thus, they can easily become clogged by foreign particulate matter present in the water supply. Further, the mist emitted from the spray nozzles 18 is susceptible to wind drift. Accordingly, a substantial amount of the water is lost before it reaches the evaporative cooling pad 12, and portions of the pad may be saturated with water while other portions of the pad are not wetted at all.
Because the amount of water that is delivered to the spray nozzles 18 is determined by the amount of time that the cycle command from the timer opens the solenoid, the amount of water emitted by the spray nozzles 18 is independent of the ambient temperature and the relative humidity of the air outside the poultry house. As a result, the evaporative cooling pad 12 may be wetted by the spray nozzles 18 even when the relative humidity of the air outside the poultry house is extremely high. Thus, the pad will be saturated and the excess water will run-off onto the ground surrounding the poultry house. Conversely, when the relative humidity of the air outside the poultry house is extremely low, the evaporative cooling pad 12 may not be sufficiently wetted to reduce the temperature of the air drawn into the poultry house to below 82 degrees Fahrenheit.
When wetted, the evaporative cooling pad 12 is substantially heavier than when it is dry, thus if the pad must be securely mounted to the superstructure of the poultry house. In addition, the evaporative cooling pad 12 must be spaced from the sidewall 14 of the poultry house sufficiently to permit the ventilation curtain 17 to be raised and lowered without interference from the pad and the mounting structure which supports the pad. A typical mounting structure 20 for securing the evaporative cooling pad 12 to the poultry house is shown in FIG. 1b. A pair of vertical joists 22, 24 are spaced outwardly from the sidewall of the poultry house beyond the ventilation curtain above and below the evaporative cooling pad 12. The pad 12 is secured along its length to the upper joist 22 by conventional fasteners and held in place against the lower joist 24 by a cable tightened by a turnbuckle (not shown). Accordingly, the fasteners and cable of the mounting structure 20 must be completely disassembled to remove and replace a damaged pad 12.
As should be apparent from the above limitations of known ventilation and evaporative cooling systems, a need exists in the poultry industry for a bracket for mounting an evaporative cooling pad, for an improved means for wetting the evaporative cooling pad, and for a means for controlling the operation of the evaporative cooling system. Accordingly, it is an object of the invention to provide a means for cooling a poultry house which does not require the use of spray nozzles which may become clogged, which may unevenly wet the pad, and which produce a fine mist that is susceptible to wind drift.
It is another object of the invention to provide a means for cooling a poultry house wherein the amount of water delivered to the evaporative cooling pad is dependent on the ambient temperature and the relative humidity of the air outside the poultry house.
It is another object of the invention to provide a means for cooling a poultry house which automatically controls the amount of water which is delivered to the evaporative cooling pad.
It is another object of the invention to provide a bracket for mounting an evaporative cooling pad which spaces the pad sufficiently from the sidewall of the poultry house to permit the ventilation curtain to be raised and lowered without interference from the bracket or the evaporative cooling pad.
It is another object of the invention to provide a bracket for mounting an evaporative cooling pad which is sufficiently strong to support a thoroughly wetted evaporative cooling pad.
It is another object of the invention to provide a bracket for mounting an evaporative cooling pad which permits a damaged pad to be removed and replaced without completely disassembling the mounting structure.